JP7333385B2 - Fast electrolyte replenishment system for aerial drones - Google Patents

Description

Cross-reference to related applications
[0001] This application claims priority to U.S. Patent Application No. 62/720,965 (filed Aug. 22, 2018), which is hereby incorporated by reference in its entirety. and its non-provisional patent application.

[0002] Metal-air batteries, specifically aluminum-air batteries, provide a high energy density power source that has promising applications as mobile and stationary distributed power sources. Metal-air batteries have the potential to replace internal combustion engines, fuel cells, and other rechargeable batteries in drone aircraft. This is because the energy density and conversion efficiency are comparable to those of hydrocarbon fuels.

[0003] Aluminum air batteries can operate in either batch mode or steady state mode. During operation of the battery, aluminum metal is consumed into the electrolyte with the formation of aluminate, resulting in saturation of the electrolyte solution and ultimately cessation of battery operation. About 1 kg of potassium hydroxide electrolyte or sodium hydroxide electrolyte allows the release of over 400 Wh of energy before being depleted and requiring replenishment.

[0004] In the steady-state mode, aluminates crystallize out of solution to form an insoluble hydroxide called hydrargillite, Al(OH) ₃ . Conventionally, these crystals are filtered from the electrolyte stream and stored for later recovery from the battery system. The recovered crystals can be transformed back into aluminum at a refurbishing facility. The advantage of this electrolyte refurbishing system is the power curve when the battery remains constant during operation, where we only need to add water and aluminum material to recharge the battery. necessary.

[0005] In batch mode, aluminum-air batteries operate until the electrolyte is saturated with aluminate. Once saturated, the aluminate must be removed for processing outside the battery system and fresh electrolyte must be introduced to continue battery operation. This system has the disadvantage of degrading the power output from the battery over time, but the overall battery system is simpler and lighter because it only needs to store the electrolyte for use. has the additional advantage of

[0006] Flying drones are being considered for many tasks that were previously performed by human-operated systems in the air. For example, drones are being used to deliver packages in the last few miles to customers, for long-distance surveys for safety of power lines or pipelines, and to monitor crop conditions on farmers' farms. used. Currently, rechargeable lithium-ion batteries are used to power drones in these applications, which severely limits flight time and range. These limits increase as payload increases. To alleviate this problem, internal combustion (IC) engines with generators or fuel cells have been installed on drones with the goal of improving the drone's range and payload. Part of the problem with these systems is the storage of flammable or explosive liquids and gases onboard, which includes the added weight of support systems for each power unit. .

[0007] Accordingly, improved methods for enabling extended use of aerial drones are desired. Unfortunately, no completely satisfactory solution has been found.
[0008] The above discussion is provided merely for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.

[0009] A metal air battery electrolyte replenishment system consisting of a base station with a docking receptor device and a matching docking probe on a flying drone. A probe onboard the drone has a sensor that guides the drone to connect to an electrolyte docking receptor on the base station. The drone uses the probe to obtain fresh electrolyte while continuing flight or during a short landing, and simultaneously to drain used electrolyte into the base station. Rapid exchange of the electrolyte allows for increased range and extended flight time without the penalty of the on-board electrolyte reconditioning system and its attendant weight.

[0010] In a first embodiment, an aerial drone system is provided. An aerial drone system comprises: an aerial drone, the aerial drone comprising: a metal-air battery; a heat exchanger; an array of sensors for detecting a receptacle; an electrolyte tank; a first bladder with one outlet valve (2) a second bladder with a second inlet valve and a second outlet valve, wherein the first bladder and the second bladder are separated by a flexible membrane an electrolyte tank; a probe fluidly connected to the electrolyte tank, the probe being (1) a first fill valve connected to a first bladder; or (2) a second bladder. a fill port selectively connected to either a second fill valve connected to the , and a drain valve selectively connected to either the first bladder or the second bladder through a common drain line and fluidly connected to the metal-air battery, the heat exchanger, and the common drain line, through the first inlet valve or the second inlet valve, respectively, to the first bladder or the second an aerial drone comprising an electrolyte pump selectively connected to any one of the bladders; a rapid electrolyte replenishment system, the rapid electrolyte replenishment system comprising: an aperture for receiving a fill port; and from a drain valve. a receptacle for receiving the probe, comprising at least one drain for receiving electrolyte; a feed pump for pumping electrolyte from the electrolyte tank to the aperture; and from the at least one drain to the electrolyte storage tank. An aerial drone system comprising: a rapid electrolyte replenishment system comprising a vacuum pump for pumping electrolyte.

[0011] In a second embodiment, a method is provided for rejuvenating the electrolyte of a metal-air battery on an aerial drone. The method comprises: docking an aerial drone with a receptacle of a fast electrolyte replenishment system, wherein docking includes inserting a fill port into the aperture; and a drain valve and a first fill valve. opening; activating the feed pump to pump electrolyte from the electrolyte tank through the first fill valve and into the first bladder while simultaneously draining the spent electrolyte from the second bladder through the common drain line; closing the drain valve and the first fill valve; and closing the second inlet valve and the second outlet valve. closing and simultaneously opening a first inlet valve and a first outlet valve so that an electrolyte pump is placed in series with the first bladder; a fast electrolyte replenishment system; and attaching and detaching the aerial drone from the receptacle of the

[0012] This brief description of the invention is intended only to provide an overview of the subject matter disclosed herein in accordance with one or more exemplary embodiments, for purposes of interpreting the claims. It is not intended to serve as a guide to define or limit the scope of the invention. The scope of the invention is defined only by the appended claims. This brief description is provided to provide a simplified introduction to a selection of example concepts that are further described in the detailed description below. This brief description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. is not intended. The claimed subject matter is not limited to only implementations that solve any or all disadvantages noted in the background.

[0013] In order that the features of the invention may be understood, the present invention may now be described in detail with reference to specific embodiments. Some of the specific embodiments are illustrated in the accompanying drawings. Since the scope of the invention may encompass other equally effective embodiments, however, the drawings depict only particular embodiments of the invention and are therefore not to be considered limiting of the scope of the invention. Note that it is not considered The drawings are not necessarily to scale and emphasis is generally placed upon illustrating features of particular embodiments of the invention. In the drawings, like reference numerals are used throughout the various views to denote like parts. Accordingly, reference may be made to the following detailed description read in conjunction with the drawings for a further understanding of the present invention.

[0014] Fig. 4 depicts a drone as docked into a fast electrolyte replenishment system; [0015] Figure 2 is a schematic diagram showing selected components of a drone; [0016] Fig. 5 is a schematic diagram showing a one-step flow path for refilling the drone with electrolyte; FIG. 4 is a schematic diagram showing a one-step flow path for refilling the loan with electrolyte; FIG. 4 is a schematic diagram showing a one-step flow path for refilling the loan with electrolyte; FIG. 4 is a schematic diagram showing a one-step flow path for refilling the loan with electrolyte; [0017] Fig. 4 is a schematic diagram of a fast electrolyte replenishment system; [0018] Fig. 4 depicts a drone probe. [0019] Figure 5A depicts the probe prior to incorporation into a fast electrolyte replenishment system; [0020] Figure 5B depicts the probe after incorporation into a fast electrolyte replenishment system; [0021] Fig. 4 depicts a receptacle of the fast electrolyte replenishment system; [0022] Fig. 4 is a cutaway view showing a receptacle for receiving a probe of the drone;

[0023] Referring to FIG. 1, a drone 100 for delivering payload 106 is shown. Drone 100 is configured for batch operation of metal-air batteries 102 that provide power to drone 100 . Drone 100 has conventional components of a drone, including propellers, a wireless communication device, and a microprocessor for controlling the functions of drone 100 . Drone system 100 further comprises an electrolyte storage tank 104 having sufficient volume to hold electrolyte over several hours of normal operation. When the electrolyte fills up with aluminate, the metal-air battery 102 drops below the power output threshold. This initiates the protocol for flying the drone 100 to the base station, where the fast electrolyte replenishment system 200 is located. During flight, the drone moves forward so that the on-board probe 400 attaches to the receptacle 500 and removes spent electrolyte while simultaneously transferring fresh electrolyte into the storage tank 104 . This happens in a matter of seconds, and drone 100 flies away to continue its mission of delivering payload 106 . This configuration removes the weight and complexity from the drone found in many conventional steady-state systems. This weight can be used directly for payload 106 and structures within the drone.

[0024] FIG. 2A is a schematic diagram of selected components of drone 100. As shown in FIG. The drone 100 comprises a tank 104 for storing electrolyte, a metal-air battery 102 and a docking probe 400 . Drone 100 includes a small pump 206 for circulating electrolyte through battery 102 and heat exchanger 208 . The tank 104 has a double bladder system separated by a flexible membrane 210 so that one bladder is full and the other is empty. This causes the filling electrolyte to push out the electrolyte in the other bladder at the same time.

[0025] Figure 2B depicts the fluid path when the metal-air battery 102 is using electrolyte from the bladder 104a. Pump 206 pumps the electrolyte from bladder 104 a through valve OUT-A, through heat exchanger 208 and into metal-air battery 102 . Electrolyte is then returned to bladder 104a through valve IN-A. The operation of the metal-air battery 102 slowly consumes the electrolyte. After a predetermined condition is met (e.g., the battery drops below a threshold power output or a predetermined operating time has elapsed), the drone will dock with the fast electrolyte replenishment system 200, at which time the fluid path will open. Change to the fluid path of FIG. 2C.

[0026] In Figure 2C, fill valve F2 and drain valve Dl are open. Pump 206 continues to pump electrolyte through the fluid path shown in FIG. 2B while fresh electrolyte is being pumped through fill valve F2 and into bladder 104b. This new electrolyte causes bladder 104b to expand, thereby compressing bladder 104a. This compression forces excess spent electrolyte out of bladder 104 a through drain valve D 1 which is connected to common drain line 204 . New electrolyte is continuously refilled and used electrolyte is removed until a predetermined amount of electrolyte has been replaced. For example, fluid replacement can continue until an amount of electrolyte equal to 90% of the volume of tank 104 has been replaced. After completion, the fluid path changes to that of FIG. 2D.

[0027] In Figure 2D, fill valve F2 and drain valve Dl are closed. At the same time, valves IN-A and OUT-A are closed, sealing bladder 104a, while valves IN-B and OUT-B are open, placing bladder 104b in series with pump 206. ing. When the electrolyte in bladder 104b is sufficiently consumed, drone 100 will dock with fast electrolyte replenishment system 200, at which time the fluid path will change to that of FIG. 2E.

[0028] The fluid path of Figure 2E is similar to that of Figure 2C, except that bladder 104a is being filled through fill valve F1, while bladder 104b is being drained through drain valve D1. do. Once filling and draining are complete, drone 100 returns to the state shown in FIG. 2B.

[0029] As shown in FIG. 3, probe 400 is docked at receptacle 500 of fast electrolyte replenishment system 200, with probe 400 fluidly connected to both electrolyte recovery line 300 and electrolyte supply line 302. be. A supply pump 308 supplies pressurized electrolyte from a fresh electrolyte tank 310 through respective fill valves F1, F2 to the current bladders 104a, 104b. A vacuum pump 304 evacuates the used electrolyte placed in the receptacle 500 and stores the used electrolyte in the used electrolyte tank 306 . The flow of vacuum air helps empty receptacle 500 quickly and also removes droplets from probe 400 as it leaves fast electrolyte replenishment system 200 . A supply pump 308 and a vacuum pump 304 on the fast electrolyte replenishment system 200 fill and empty the bladder using an onboard pump 206 that continuously circulates electrolyte through the battery 102 on the drone 100 . to Advantageously, this allows electrolyte replacement while the battery 102 is in operation.

[0030] Figure 4 depicts the probe 400 in greater detail. Probe 400 has elongated protrusions that help guide probe 400 to receptacle 500 of fast electrolyte replenishment system 200 . Probe 400 has a central fill port 400a at the end of the elongated projection leading to both fill valve F1 and fill valve F2. There is an array of sensors 402 that assist in positioning the probe 400 within the receptacle 500 . In one embodiment, there are at least two sensors 402 separated by a distance (d) of at least 1 cm. Such a configuration allows stereoscopic viewing of the receptacle 500 to facilitate docking. In one embodiment, sensor 402 is a three-dimensional (3D) stereo camera. There is also at least one O-ring 400c on the probe 400 that fits into the receptacle 500 to allow electrolyte to be pumped into the onboard tank 104 at high pressure. Drain hole 400 b is connected to drain valve D 1 to release spent electrolyte into receptacle 500 . The receptacle 500 is placed at a sufficient height above the ground or surface so that the clearance of the drone 100 allows refueling while in flight or while landing on a small platform. . 5A and 5B provide a more detailed view of docking probe 400 into receptacle 500. FIG.

[0031] As shown in Figure 5A, a receptacle 500 has a droplet cup 502 defined by a wall 506 and a central aperture 504 at the bottom. A central aperture 504 is surrounded by a drain vacuum hole 600 ( FIG. 6 ) that is fluidly connected to the electrolyte recovery line 300 . A central aperture 504 is fluidly connected to the electrolyte supply line 302 . As probe 400 approaches receptacle 500, elongated projection 404 is inserted into central aperture 504 until o-ring 400c engages the surrounding wall. FIG. 5B depicts the assembly after engagement. Fresh electrolyte is provided through electrolyte supply line 302 , while used electrolyte is drained through drain hole 400 b and flows into drain vacuum hole 600 . The presence of the drip cup 502 eliminates the need for the drain hole 400b to form a liquid tight seal with the drain vacuum hole 600. FIG. FIG. 7 is a cutaway view of receptacle 500 further showing drain vacuum hole 600 and central aperture 504 .

[0032] In some embodiments, there is a network with multiple systems doing work for multiple drones. Each fast electrolyte replenishment system 200 has a computer network that reports electrolyte availability to a central network, so that the work of each individual system can be performed in a timely manner so that other drones can , it is possible to determine which stations are full of electrolyte or lack electrolyte. Global Positioning System (GPS) coordinates for each fast electrolyte replenishment system 200 are used to guide the drone 100 to the approximate location, and to fill and drain the drone 100. In the last 0.5 meters the coalescence is done visually.

[0033] The drone 100 has a microprocessor for selectively actuating each valve according to pre-programmed instructions. The microprocessor also monitors the fill status of bladders 104a, 104b to determine the volume of each bladder during the refill/drain process. The volume of each bladder is determined using any of a variety of conventional sensors, such as pressure sensors, ultrasonic sensors, and the like.

[0034] This written description is intended to disclose the invention, including the best mode, and also to make and use any device or system and to implement any embodied method. The examples are used to enable those skilled in the art to practice the invention, including the following. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. If such other examples have structural elements that do not differ from the claim language or contain equivalent structural elements that do not differ significantly from the claim language, such other examples are also intended to be within the scope of the claims.

Claims (10)

An aerial drone system, the aerial drone system comprising an aerial drone and a rapid electrolyte replenishment system,
The aerial drone is
metal air battery;
Heat exchanger;
an array of sensors for detecting sockets;
An electrolyte tank comprising: (1) a first bladder comprising a first inlet valve and a first outlet valve; (2) a second bladder comprising a second inlet valve and a second outlet valve; an electrolyte tank comprising: said first bladder and said second bladder separated by a flexible membrane;
A probe fluidly connected to the electrolyte tank, the probe:
a fill port selectively connected to either (1) a first fill valve connected to the first bladder; or (2) a second fill valve connected to the second bladder; and a drain valve selectively connected to either the first bladder or the second bladder through a common drain line; and
fluidly connected to the metal-air battery, the heat exchanger, and the common drain line and through the first inlet valve or the second inlet valve, respectively, to the first bladder or the second bladder; an electrolyte pump selectively connected to one of the bladders;
with
The high-speed electrolyte replenishment system includes:
the receptacle for receiving the probe, the receptacle comprising:
an aperture for receiving said fill port; and at least one drain hole for receiving electrolyte from said drain valve;
the receptacle, comprising;
a feed pump for pumping electrolyte from an electrolyte tank to said aperture; and a vacuum pump for pumping electrolyte from said at least one drain hole to an electrolyte storage tank.
comprising
aerial drone system. 2. The aerial drone system of claim 1, wherein the fill port further comprises an elongated protrusion that fits within the aperture of the receptacle. 3. The aerial drone system of claim 2, wherein said elongated protrusion comprises at least one O-ring. 2. The aerial drone system of claim 1, wherein the at least one drain hole is located within the drip cup of the receptacle. 2. The aerial drone system of claim 1, wherein the at least one drainage hole comprises a plurality of drainage holes. 6. The aerial drone system of claim 5, wherein said aperture is surrounded by said plurality of drainage holes. 2. The aerial drone system of claim 1, wherein the array of sensors includes a first sensor and a second sensor separated by a distance of at least 1 cm. 2. The aerial drone system of claim 1, wherein the array of sensors includes a three-dimensional (3D) stereo camera. A method for recovering the electrolyte of a metal-air battery on an aerial drone, the method comprising:
docking the aerial drone of claim 1 into a receptacle of a rapid electrolyte replenishment system of claim 1, wherein docking comprises inserting a fill port into an aperture;
opening the drain valve and the first fill valve;
A supply pump is actuated to pump electrolyte from the electrolyte tank through the first fill valve and into the first bladder while simultaneously discharging spent electrolyte from the second bladder through a common drain line. operating a vacuum pump to collect into the at least one drain hole;
closing the drain valve and the first fill valve;
closing a second inlet valve and a second outlet valve and simultaneously opening a first inlet valve and a first outlet valve so that an electrolyte pump is in series with the first bladder; a step located in;
and detaching the aerial drone from the receptacle of the fast electrolyte replenishment system. docking the aerial drone with the receptacle of the fast electrolyte replenishment system;
opening the drain valve and the second fill valve;
actuating the supply pump to pump electrolyte from the electrolyte tank through the second fill valve and into the second bladder while simultaneously draining the first bladder through the common drain line; collecting spent electrolyte in said at least one drain hole;
closing the drain valve and the second fill valve;
closing the first inlet valve and the first outlet valve and simultaneously opening the second inlet valve and the second outlet valve, so that the electrolyte pump is a step disposed in series with the bladder of;
and detaching the aerial drone from the receptacle of the fast electrolyte replenishment system.
10. The method of claim 9.

Images